[torqhead]

After paying others to build auto transmissions for me I decided Covid would help me learn how to work on automatics since once again I found myself on the side of the road. Keep in mind this is the 4th build on this transmission.

I've worked on cars for 40+ years and worked on every part of a car, including manual transmissions but never an automatic. Well now that I've actually opened up a 700R4, I would confidently say it's nuts to put one of these transmissions behind anything that makes any power. The main input shaft to aluminum drum is the weak point. And contrary to using a sonnax reinforcement ring, it's just a plain waste of time. Take a look at the pic and you'll see why as I had the reinforcement ring installed in mine. All the power goes into the main input shaft that's pressed into the aluminum drum, the input shaft is 1.1 inch's thick. Seems like a basic physics problem to me...

So I've decided not to install this back in the car and looking at putting a 4L80 in place. Anyone ever done this swap? I searched the forum first before asking here., don't yell at me if my search skills suck. I would like my factory speedo and quadrajet in place. Any guidance would be appreciated.